This invention relates generally to the field of article identification and more specifically to an enhancement antenna for article identification.
Article identification systems generally comprise a reader that captures information about an article by reading a tag affixed to the article. Examples of some article identification systems in the market include bar code scanning systems, magnetic sweeping systems, active transponder systems, and passive transponder systems. Transponder systems have an advantage over other systems in that no direct line of sight is required. Even with that advantage, however, the tag may be read only from distances less than approximately one to two meters. This distance may require close proximity between the reader and the tag, limiting the feasibility of reading a large quantity of articles scattered throughout a large area. Known techniques for increasing the distance from which information may be captured include enlarging the tag, increasing the power of the reader, and enlarging the reader antenna. These techniques, however, may be impractical because governmental regulations restrict the power of the reader and the size of the reader antenna. Additionally, enlarging the tag may not be desirable because doing so increases the cost of the system. Consequently, known techniques of article identification are unsatisfactory in certain situations.
In accordance with the present invention, disadvantages and problems associated with previous techniques for enhancing article identification may be reduced or eliminated.
According to one embodiment, an article identification system includes a transceiver that generates a request signal and transmits the request signal, where the request signal requests information corresponding to an article. A transponder is coupled to the article, receives the request signal, and generates an output signal in response to the request signal, where the output signal includes information corresponding to the article. A loop antenna proximate to the transponder enhances the output signal. The transceiver detects the enhanced output signal and receives the information corresponding to the article.
Certain embodiments of the invention may provide one or more technical advantages. A technical advantage of one embodiment may be that a loop antenna may be used to enhance the output signal of a transponder. Accordingly, the distance between a transceiver and a transponder may be increased while maintaining the power of the transceiver and the size of a transceiver antenna.
Certain embodiments of the invention may include none, some, or all of the above technical advantages. One or more other technical advantages may be readily apparent to one skilled in the art from the figures, descriptions, and claims included herein.